Add BYOC support to create_index, describe_index, list_indexes

[jhamon]

Problem

BYOC requires a new type of spec object, ByocSpec.

Solution

• Update legacy-style methods to accept new ByocSpec type:
  • Pinecone#create_index
  • PineconeAsyncio#create_index
• Update resource classes (accessed from pc.db.index.create)
  • IndexResource#create
  • AsyncioIndexResource#create
• Update interfaces used for docgen

Type of Change

• New feature (non-breaking change which adds functionality)

Test Plan

• Added a new unit test to ensure the client can properly deserialize API responses (e.g. from describe, list) that include the new byoc spec type into the IndexModel object. This is important since I'm currently not set up to do a full integration test of the feature.